#include<bits/stdc++.h>

using namespace std;
typedef long long ll;

struct Fraction {
    ll top;//分子numerator
    ll bottom;//分母denominator
};

ll gcd(ll a, ll b) {
    if (b == 0)return a;
    return gcd(b, a % b);
}

void simplify(Fraction &f) {
    ll g = gcd(f.top, f.bottom);
    f.top /= g;
    f.bottom /= g;

}

void input(Fraction &f) {
    cin >> f.top >> f.bottom;
    simplify(f);
}

void output(Fraction f) {
    printf("%lld/%lld\n", f.top, f.bottom);
}

Fraction add(Fraction a, Fraction b) {
    Fraction c = {0, 1};
    c.top = a.top * b.bottom + a.bottom * b.top;
    c.bottom = a.bottom * b.bottom;
    simplify(c);
    return c;
}

int main() {
    int i;
    Fraction s = {0, 1};//int s=0;
    for (i = 1; i <= 20; i++) {
        Fraction f = {1, i};
        s = add(s, f);
    }
    output(s);
    cout << 55835135.0 / 15519504 << endl;
    double t = 0;
    for (int j = 1; j <= 20; j++) {
        t += 1.0 / j;
    }
    cout << t << endl;
    return 0;
}